Soil and stain resistance and soil and stain release properties in textile articles

ABSTRACT

TEXTILE ARTICLES OF CELLULOSIC FIBERS, NON-CELLULOSIC FIBERS AND ARTICLES COMPRISING BLENDS OF CELLULOSIC AND NON-CELLULOSIC FIBERS, WITH IMPROVED SOIL AND STAIN RESISTANCE QUALITIES AND SOIL AND STAIN RELEASE QUALITIES, ARE PRODUCED BY CONTACTING THE ARTICLES WITH A FINISHING MIXTURE COMPRISING AN ALDEHYDE-RELEASING COMPOUND, ANIMAL GLUE AND A PLASTICIZER FOR THE ANIMAL GLUE; AND BY CURING THE FINISH.

Patented June 1,, 1971 SOIL AND STAIN RESISTANCE AND SOIL AND STAIN RELEASE PROPERTIES IN TEXTILE ARTICLES Julian J. Hirshfeld and Bertie J. Reuben, Decatur, and

John W. Bullington, Athens, Ala., assignors to Monsanto Company, St. Louis, M0. N Drawing. Filed May 10, 1968, Ser. No. 728,339

Int. Cl. D06m 9/00 US. Cl. 8-115.6 13 Claims ABSTRACT OF THE DISCLOSURE Textile articles of cellulosic fibers, non-cellulosic fibers and articles comprising blends of cellulosic and non-cellulosic fibers, with improved soil and stain resistance qualities and soil and stain release qualities, are produced by contacting the articles with a finishing mixture comprising an aldehyde-releasing compound, animal glue and a plasticizer for the animal glue; and by curing the finish.

BACKGROUND OF THE INVENTION This invention relates to textile articles including fabrics consisting essentially of cellulosic fibers or of noncellulosic fibers and fabric blends of both, and more particularly to a process for finishing textile articles including fabrics whereby soil and stain resistance and soil and stain release properties are enhanced.

In the textile field and particularly in the carpet industry, where in recent years pastel colors and the use of carpets next to entry-Ways have become popular, the need for anti-soiling characteristics built into textile articles has become more prevalent. Also, the increased use of hydrophobic fibers, such as nylon, polyester, and acrylic, in textile articles has increased such a need since these fibers accumulate static charges of electricity and thus attract soiling particles.

Soiling of textile articles is generally affected by three methods, i.e. by directly contacting the article with soiling particles, by contacting the article with air-borne soiling particles, and by contacting the article with liquidborne substances containing soiling particles. Retention of the soiling particles on the textile article can be explained by three basic mechanisms, i.e. purely mechanical forces of entrapment or occulsion, interfacial adhesion forces such as Van der Waals forces, and electrostatic forces.

Since formaldehyde combines with alcohols in the presence of acid to form the hemi-acetal, which is unstable and reacts rapidly to give the acetal (formal):

it is probable that it cross-links cellulose under resin-curing conditions:

and although there is no absolute proof, it is a generally accepted theory that such cross-linking does occur.

Testing of formaldehyde treatments of cellulose at controlled degrees of swelling has revealed that 410% formaldehyde appeared to react with cellulosic fibers, and that the resulting product could swell greatly in water and had excellent wet crease recovery.

This invention utilizes the theory that formaldehyde, alone, or in conjunction with conventional resin finishes, cross-links cellulosic fibers (when cellulosic fibers are included in the fabric), and, at the same time, reacts with animal glue or gelatin to provide a textile article with improved soil and stain resistance and soil and stain release qualities, as well as a maximum of crease-retention properties. And with respect to non-cellulosic fibers, where cross-linking is not involved, the finish will nevertheless provide good qualities of soil and stain resistance and soil and stain release.

Permanent press finishes are most effectively applied to fabric blends of cellulosic and non-cellulosic fibers because there is a significant strength loss on the part of cellulose when finished with the durable press finishes. Since this strength loss range from 40 to 50%, synthetic fibers of polyester, nylon or acrylics are commonly used to maintain within the finished product a strength that is sufiicient for the prospective end use. Accordingly, a finish which has a lasting effect on synthetic fibers, as well as cellulosic fibers is particularly useful where permanent press characteristics are desired in the finished article.

SUMMARY OF THE DISCLOSURE It is a primary object of this invention to provide a process for improving soil and stain resistance and soil and stain release properties in textile articles including fabrics consisting of cellulosic fibers and/ or non-cellulosic fibers.

This and other objects and advantages will become apparent in the course of the following specification, examples and appended claims.

Briefly, the object of this invention is accomplished by applying to the article a mixture of an aldehyde-releasing compound, animal glue or gelatin, and a plasticizer for the animal glue such as sorbitol or glycerin; and then curing the finish.

DESCRIPTION OF THE PREFERRED EMBODIMENT The term textile article is meant to include fiber, yarn, all types of fabric, all types of carpets, and any textile article made of fiber. The textile article can be comprised of a natural fiber, a synthetic fiber or a combination of a natural and a synthetic fiber. Other types of material useful in textile articles and of common knowledge to the textile art may be present in minor portions. Examples of useful natural fibers include cotton, wool, silk, etc. The term synthetic fiber is meant to include all truly synthetic fibers and all man-made fibers. Examples of synthetic fibers include rayon fiber (a manufactured fiber composed of regenerated cellulose as well as manufactured fibers composed of regenerated cellulose in which substituents have replaced not more than 15% of the hydrogens of the hydroxyl groups), acetate fiber (a manufactured fiber in which the fiber-forming substance is cellulose acetate; where not less than 92% of the hydroxyl groups are acetylated, the term tri-acetate may be used as a generic description of the fiber), spandex fiber (a manufactured fiber in which the fiber-forming substance is any longchain synthetic polymer of at least 'by weight of a segmented polyurethane), polyester fiber (a manufactured fiber in which the fiber-forming substance is any longchain synthetic polymer composed of at least 85% by weight of an ester of a dihydric alcohol and a dibasic acid or derivative thereof, such as terephthalic acid and and dimethyl terephthalate), olefin fiber (a manufactured fiber in which the fiber-forming substance is any longchain synthetic polymer composed of at least 85% by weight of ethylene, propylene or other olefin units), modacrylic fiber (a manufactured fiber in which the fiberforming substance is any long-chain synthetic polymer composed of less than 85 but at least 35% by weight of acrylonitrile units), nylon fiber (a manufactured fiber in which the fiber-forming substance is any long-chain synthetic polyamide having recurring amide groups as an integral part of the polymer chain), and acrylic fiber (a manufactured fiber in which the fiber-forming substance is any long-chain synthetic polymer composed of at least 85 by weight of acrylonitrile units).

Many of the commercially available crease-retention type finishes include formaldehyde in the resin system, or liberate formaldehyde during the curing process. These resin reactants include the urea-formaldehydes such as monomethylol urea, dimethylol urea and trimethylol urea; the melamine-formaldehydes including trimethylol melamine, hexamethylol melamine, and hexamethylol isomelamine; the propylene ureas including dimethylol propylene urea and dihydroxy dimethylol propylene urea; the imidazolines, including dihydroxy dimethylol ethylene urea; the carbamates, including dimethylol ethyl carbamate, dimethylol methyl carbamate, and dimethylol isopropyl carbamate, the urons, including dimethylol uron and dimethyl N-methylol uron; the triazones including ethyl triazone; and the acetals. The scope of this invention does not include the finishing of textile articles with the above mentioned resin reactants.

Other commonly used crease-retention resins which do not have formaldehyde inherent in the system, but which may be used in conjunction with the application of the instant invention, include such sulfones as sulfonyl diethanol and similar sulfones that cure on the alkyline side, the vinyl sulfones including beta-methoxy ethyl vinyl sulfone and the epoxy reactants. The technique of employment of each is within the knowledge of those skilled in the art.

Animal glue suitable for use in accordance with this invention is an impure gelatin obtained from animal organs by boiling with water, and drying, and is usually supplied commercially in thin, hard and brittle cakes. Various glue or gelatin materials of animal origin which are commercially available include acid-conditioned or lime-conditioned collagen from frozen park skins and lime-conditioned collagen from calf skins, beef hides, and ossein. The molecular weight of this natural polymer varies from about 20,000 up to about 250,000. Animal glue is essentially composed of polyamides of certain alpha-amino acids. It is believed that the amino acids are present not in the free state but rather as residues which are joined together by the elimination of water to form long polypeptides chains. Examples of some of the amino acids present in animal glue are glycine, proline, alanine, hydroxyproline, glutamic acid, arginine, aspartic acid, leucine, valine, phenylalanine, isoleucine, methionine, hydroxylysine, histidine, and tyrosine. Also it has been postulated that the animal glue molecules consist of single polypeptide chains terminated at one end by an amino group and at the other end by a carboxyl group. Description of useful animal glues can be found in Irvin Skeist, Handbook of Adhesives, 114-125 (1962); and in vol. 7, Kirk & atlugnqr, Encyclopedia of Chemical Technology, 207-215 Animal glue is generally an amber colored material which exhibits a crystal-like appearance in the dried ground form. Having no definite melting point, animal glue decomposes when heated to its charring temperature, At temperatures of 100150 C., the glue exhibits a decreased solubility and an increased viscosity. Like most proteins, animal glue absorbs water readily and forms an elastic gel which readily melts at about 40-50 C. to form a viscous solution having great adhesive properties. One of the characteristic properties of animal glue is its tendency to form reversible gels in aqueous solutions. Such gels are characteristic of increasing in rigidity with lower temperatures and rising concentrations. Gelation of animal glue solutions can be prevented or retarded by the addition of inorganic soluble salts, e.g. salts of the alkali earth metals. Also, certain organic substances such as urea, thiourea and phenyl exhibit this liquefy-ing power. Aqueous solutions of animal glue are quite stable over a wide range of pH values, e.g. 3.0-l0.0, without appreciable decomposition. The peptide units within the polymer of animal glue are subject to hydrolysis at temperatures above about 65 C. and boiling of an aqueous solution of animal glue breaks down both the viscosity and jelly strength thereof and, in the presence of mineral acids or alkalies, such decomposition is almost instantaneous. An example of a useful animal glue is obtained by the hydrolysis of collagen:

wherein the chemical composition is:

The use of glue in accordance with this invention is not restricted to any particular source of gelatin material. Nor is the Bloom value of the glue of particular significance. The etTect of formaldehyde on glue is well known in the glue arts. Even a trace, .4% or more, based on the weight of the glue, will solidify the glue into a substance which is insoluble in water. As the proportion of formaldehyde to glue increases beyond 16%, there is a decrease in the relative strength of the glue as the proportion of formaldehyde is increased; and as the proportion of formaldehyde exceeds about 50% the amount of the gelatin, there will be a deterioration in the soil resistance and soil re lease properties of the finished fabric as the fabric is repeatedly washed.

The amount of formaldehyde which will be absorbed by glue alone and which will provide maximum strength in the glue is within a range of 4-8% based on the weight of the glue. This is the desirable amount of formaldehyde in the finish mixture when the fabric is comprised essentially of synthetic fibers. As the percentage of cellulosic fibers in a fiber blend is increased, however, the amount of formaldehyde which reacts with cellulose should be added to the amount absorbed by the glue in determining a theoretically ideal proportion. The amount of formaldehyde which will react with and cross link cellulose under resin-curing conditions is known to approximate 5.8% in the case of dry cellulose and from about .4% to about 1.5% in the case of swollen cellulose, these percentages being based on the weight of the cellulose fiber. The immediate reactivity of formaldehyde and animal glue makes it impractical to use formaldehyde or any free aldehyde-containing solution in accordance with this invention. Common aldehyde-releasing compounds also known as formaldehyde donors decompose upon exposure to heat to release the aldehyde. Such compounds include monomethylol and dimethylol hydantoin, para-formaldehyde, drioxane and hexamethylene tetramine.

Suitable plasticizers for the animal glue in accordance with the instant invention include all alcohols, but preferably one of the polyhydroxy alcohols, as, for example, sorbitol or glycerine. The plasticizers have no effect on the soil resistance or soil release properties of the fabric. Their only purpose is to prevent the glue from unduly adversely effecting the hand of the fabric. Therefore, where a soft hand is unnecessary or undesirable, the plasticizer may be omitted entirely. For most purposes, it has been found that a minimum of about 20% of a polyhydroxy alcohol based on the weight of the glue will provide a good hand in most fabrics. An excess in the amount of the alcohol plasticizer will not create an unsatisfactory product; however no useful purpose is served by including a polyhydroxy alcohol in excess of about 500% based on the weight of the glue.

It may of course be desirable to add other agents to the finish mixture in order to impart particular results. The inclusion of a rust inhibitor may be desirable where treated fabrics are likely to contact metals. A plasticizer or softening agent may also be included as an optional ingredient in order to provide a more desirable hand or texture to the treated fabric. It has been found that the cationic softening agent hydroxyl alkyl glyoxalidine can be employed for this purpose. Softening agents are normally employed in amounts of from about 1 to about 15% based on the weight of the total composition.

Contacting the textile article with the finish mixture can be accomplished by immersion, padding, spraying, roll application and any other such process known in the textile art. The contacting should be for a sufiicient time to completely wet and impregnate the article. For example a contact time within the range of from about minutes to about 90 minutes will generally be adequate to wet the textile article. A contact time of about 30 minutes is a preferred time. Padding contact time is from a fraction of a second to 2 seconds.

According to this invention the plasticizer is mixed with an aqueous solution of the animal glue, which mixture is, in turn, added to the resin formulation if such is to be used. The donor is added, after which the article is contacted with the mixture and subsequently cured.

Following impregnation with the above described treating composition, the treated fabric is dried and heated to cause reaction of the resin formulation, in situ, and to cure the resinous finish, if resin is used in conjunction with the formaldehyde and glue. Where a resin is employed, drying and curing of the treated fabric may be accomplished in separate steps or in a single operation if preferred. When drying is carried out as a separate step it may be done either at normal ambient air temperatures or at elevated temperatures from about 200 F. to about 250 F., leaving a residual moisture content of 5-8%. Following the drying operation whether it be accomplished at normal temperature or by heating, the dried impregnated textile is brought to a temperature within the range of from about 260 F. to 350 F. The higher the temperature, the shorter is the period of heat treatment. Thus, drying the impregnated textile for 20 minutes in an oven maintained at a temperature of about 210 F. followed by heating at a higher temperature, for example, :8 minutes at 290 F. or for 4 minutes at 320 F., is generally effective in obtaining the desired results. These specific time and temperature periods are merely illustrative of those that can be employed.

Where resin is not employed in conjunction with the animal glue and the aldehyde donor, curing of the finish may be accomplished by the resin-curing steps described above, or by simply drying the impregnated textile for 20 minutes in an oven maintained at a temperature of about 210 F., the drying step sufiicing to cross link any cellulosic fibers and to react the formaldehyde with the animal glue.

Although as stated above, the application of this invention is especially suited and most effective when used with cellulosic fibers because the principles of cellulose reactivity are involved in cross-linking the cellulose by means of its available hydroxyl groups which are reactive sites for the resins and reactants, this process has an important significance in connection with the non-cellulosic synthetic fibers in fabric blends, and even with respect to fabrics composed solely, or in part solely of synthetic fibers. Even with the absence of available hydroxyl groups on the synthetic fibers, the use of the animal glue with its tendency to adhere to any fiber, creates, on the part of the non-cellulosic fibers a durable finish coating.

The following examples will serve to illustrate specific embodiments of this invention.

6 EXAMPLE I The following non-resin mixtures were padded to nylon taffeta swatches after which samples were dried at 190 F. and then cured for 5 minutes at 300 F.:

Sample 1: Percent Animal glue 22.6 Diethylene glycol 22.1

2 55.3 Sample 2:

Animal glue 36.3 Diethylene glycol 8.3 Glycerine 8.3 H 0 47.1 Sample 3:

Am'mal glue 22.6 Diethylene glycol 22.1 Para formaldehyde 2.6 Water 52.7

Sample 4:-

Animal glue 36.3 Glycerine 8.3 Diethylene glycol 8.2 Para formaldehyde 3.6 Water 43.5

Sample 5:

Animal glue 22.6 Sorbitol 22.1 Water 55.3

Sample 6:

Animal glue 36.3 Sorbitol 16.6 Water 47.1 Sample 7:

Animal glue 22.6 Sorbitol 22.1 Para formaldehyde 2.6 Water 52.7 Sample 8:

Animal glue 36.3 Sorbitol 16.6 Para formaldehyde 3.6 Water 43.5

All samples were pre-scoured with .25 g./l. of com mercially available Fab detergent containing no optical brightener. The scouring was at a temperature of 140 150 F. for a period of 15 minutes. Samples were'then rinsed, dried, and allowed to condition at room temperature and humidity. Their original reflectance was then read against a white background with a Photovolt Reflectance Meter (Model No. 610, Photovolt Corp., New York, N.Y.). These readings are as shown on Table 1 under Original Whiteness.

Each sample was then placed in a liter screw-cap jar containing millimeters of a soiling solution, and the jar was agitated for a period of 5 minutes to insure that the sample was thoroughly saturated and well exposed to the mixture.

The soiling solution was prepared in the following manner. 100 gram mixture consisting of W Percent Palmitic acid 10 Stearic acid 5 Coconut oil 15 Parafi'in 10 Spermaceti 15 Olive oil 20 Squalene 5 Cholesterol 5 Oleic acid 10 Linoleic acid 5 was heated to B, after which was added Grams Oleic acid v L 4 Triethanolamine 8 Airborne soil 4 The above was mixed thoroughly and added to an equal volume of water at 130 F. in a Waring Blendor. After being homogenized for 15 minutes. the mixture was diluted to a liter and homogenized for another 15 minutes:

The samples were then removed from the screw-cap jars and passed through squeeze rolls with pressure adjusted on the rolls to provide cotton broad-cloth (3.1 oz./ sq. yd.) with a wet pick-up of 7 -80%. All samples were then hung in a circulating air oven set at 180-185 F. for minutes. After drying, all samples were washed in a Tirgotometer (U.S. Testing Co.) at 130 F. for 10 minutes at a :1 liquor-to-fabric ratio using 1 gram per liter of Tide, a detergent soap manufactured by Procter & Gamble. Samples were rinsed, dried and again measured for reflectance with the Photovolt Reflectance meter. Results of the second sample readings are at Table 1 under After Soiling and Washing.

TABLE 1 Whiteness after soiling 0 riginal and Percent whiteness washing soiled Sample No.:

1 80. 3 69. 8 l3. 0 79. O 73. 0 7. 6 80. 8 74. 3 8. 1 79. 7 .75. 7 .5. 0 80. 7 69. 2 l4. 3 80. 2 74. 0 7. 7 31. 4 75. 7 7. 1 B1. 2 75. 8 7

EXAMPLE II Samples used were identical with those used in Example I. The finishin procedures were identical except that although the finishes were dried at 190 they were not cured. The reflectance measurements, soiling and Washing processes were identical.

TABLE 2 Whiteuess after soiling Original and Percent whiteness washing soiled B1. 2 71. 7 l1. 7 79. 5 69. 5 12. 6 80. 0 74. 3 7. 1 80. 0 74. 0 7. 5 80. 0 76. 7 4. 1 .81. 0 7-1. 0 l8. 7 30. 8 74. 7 7. 6 79. 8 75. 2 5. 8

EXAMPLE III Samples 9-17 were swatches of cotton poplin composed of 65% polyester and cotton. The swatches were treated with non-resin finishes as described in Example I for samples l-8 respectively. They were dried and cured in the same manner and tested in the same manner as in Example I, with the following results:

EXAMPLE IV Samples used and finish composition were identical with those in Example III. Finish r rocessing was identical except that although the impreg rgtted samples were dried lllllll NW NW 8 at F., the curing step was omitted. Reflectance readings, soiling and washing procedures were identical.

It will be obvious to one skilled in the art that the formulas used in the above examples can be modified Without departure from the scope of the present invention.

We claim:

1. A process for providing a soil resistant and soil release finish to a textile article comprising the steps of contacting said article with an aqueous mixture comprising animal glue, an alcoholic plasticizer for said animal glue and an aldehyde releasing compound selected from the group consisting of monomethylol hydantoin, dimethylol hydantoin, paraformaldehyde, drioxane and hexamethylene tetramine.

2. The process of claim 1 wherein fabric.

3. The process of claim 1 wherein fabric comprising cellulosic fibers.

4. The process of claim 1 wherein said article is a fabric comprising a blend of cellulosic fibers and noncellulosic fibers.

5. The process of claim 1 wherein said article is a filament.

6. A process for providing a soil resistant and soil release finish to a textile article comprising the steps of app-lying to said article an aqueous mixture comprising animal glue, an alcoholic plasticizer for said animal glue and an aldehyde donor compound selected from the group consisting of monomethylol hydantoin, dimethylol hydantoin, paraformaldehyde, drioxane and hexamethylene tetramine so as to impregnate and wet said article; and then drying and curing said article by exposure to heat for at least about 20 minutes at a temperature of at least about 200 F.

7. The process of claim 6 wherein said article is a fabric.

8. The process of claim 6 wherein said article is a. fabric comprising cellulosic fibers.

9. The process of claim 6 wherein said article is a fabric comprising a blend of cellulosic fibers and now cellulosic fibers.

10. The process of claim 6 wherein said article is a filament.

11. A soil resistant finished textile article produced by the process of claim 1'.

12. A soil resistant finished fabric comprising cellulosic fibers produced by the process of claim 1.

13. A soil resistant finished fabric comprising cellulosic fibers and synthetic fibers produced by the process of claim 1.

said article is a said article is a References Cited UNITED STATES PATENTS 3,535,141 4/1967 Marco l17-47 2,884,301 4/1959 Beaumont 8l16.2 3,147,065 9/1964 Koshar 8l16.2 3,362,782 l/1968 Domenick 81 16.3

GEORGE F. LESMES, Primary Examiner l3. BETTIS, Assistant Examiner U S. c1. x 11. 81E5.7, i16.i,116.3;260 6 

